THE GROWTH-HORMONE INSULIN-LIKE GROWTH-FACTOR AXIS IN INTRAUTERINE GROWTH-RETARDATION - PATHOPHYSIOLOGICAL AND THERAPEUTIC IMPLICATIONS

Our understanding of the hormonal control of growth during the fetal p eriod is incomplete, and it is inapparent how the short stature associ ated with intrauterine growth retardation (IUGR) might be prevented or treated, There is evidence that insulin-like growth factors (IGFs) pl ay important roles in the regulation of perinatal growth, Ro dents gen etically engineered to lack either IGFs or IGF receptors display prena tal and postnatal growth retardation, depending on the specific gene a ffected, Humans with IUGR frequently have low concentrations of IGF-I. Because some patients with IUGR associated short stature may have rel atively decreased growth hormone (GH) secretion, GH treatment could be beneficial. Recent reports show gains in height for some patients whe n GH treatment is continuous and at a moderately high dosage. Patients with laboratory evidence for relatively lower GH secretion seem to re spond better, These published studies, however, lack untreated control s and evaluate a paucity of patients treated to final height. Challeng es for the future include the development of better methods of predict ing who may respond to GH therapy, increasing our understanding of the mechanisms that control human growth in the perinatal period, and con ducting well controlled studies that will determine whether GH treatme nt of patients with IUGR-associated short stature will produce meaning ful gains in adult height.